Making the 6X6.8

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flowj

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So I got my Hornady dies. Started with new old stock SSA brass. Lubed and sized the first one. Chambered in rifle. Could not eject with charge handle. Used a screw driver thru mag well to eject. Set die as low as it would go for more bump. Measured brass length it was 1.686 to .688. Sized 32 more all were right at or over max. length. Trimmed all to 1.676 and chamfered. Chambered one it was a little tight but would eject with charge handle. My question is does anyone know what the outside dimension for the neck is on the reamer? My brass measures a true .266 but the thickness measures .012 to .015. The factory 6.8 brass measured .012 to .0125 thickness. I realize that when you shrink the neck that brass has to go somewhere and some of it went to the length but I assumed it would be more true in the neck thickness. What I don't know is it a concentricity problem with the die or just random brass bunching. Anyone else measured neck thickness after forming to 6MM?
 
It's a 274 neck. My loaded Starline, new batch, is running about 266. On your new brass you shouldn't bump the shoulder at all. Set the die up to only size the neck down and try a couple that way.

If once you get a couple fired cases and if the bump on the shoulders isn't enough grind 0.010 off the top of the holder. That will give you plenty of adjustment.

Greg

Was this NEW brass? Case growth will be very minimal on the new stuff since the brass hasn't expanded and need to be squeezed in and up.
 
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It is new brass. When I first set up the die I left about.005 between shell holder and die. But when the sized case did not want to eject I ran the die down all the way. I didn't know if it was a shoulder thing or maybe excessive length causing the ejection problem. Also the gun has a brand new BCG in it. I guess it could have a burr on it causing the problem. After trimming & full sizing I can eject with charge handle. My biggest concern is the inside of neck. The thickness being .012 on one side and .015 on the other. The outside measurements are concentric .266 all the way around. I did not measure these 33 cases for neck thickness before reforming but have measured all the other new brass & it is pretty uniform at .012 to .0125. I am assuming they ream a die just like a chamber with a one piece reamer so it should be impossible to get the neck bore and the body bore out of alignment. My press is a 40 yr old Rockcucker but I've loaded some pretty accurate ammo for my bolt guns with it. However other than making 7mm TCU rounds out of .233 years ago, this is the first time I've made a wildcat cartridge. I guess all I can do is load and shoot them. I hope some of the other guys chime in on their brass measurement after forming. Thanks
 
If that 266 is a loaded round you have nothing to be concerned about. The chamber being 274 us plenty big.

I never trim freshly made cases. When you fire them they will shorten up. The chamber has plenty of room to accommodate the slightly increased neck length.

Greg
 
That is unloaded spec. I haven't loaded any yet. I never thought about them shortening after they conform to the chamber. That makes sense. Not having a print of the chamber dimensions I didn't know how close the length of the neck bore was to max length. I will keep these 33 cases seperate from any more I form till I get this figured out. Thanks for the input Greg.
 
The best approach I've found is to make up three cases that fit in the camber and go shoot them. Then I have shoulder height parameters. If the shoulder has to be bumped I size cases enough so that when they extract, unloaded, smooth as cat gut I am happy. Remember the new brass has a shoulder that is usually about 0.004- 0.008 below minimum size of the parent so you don't have to bump the shoulders on new cases.

The "shelf" is 1.694 on this chamber so you have plenty of room even with your newly formed cases. Also the length will get a bit short, minuscule, when you seat a bullet.

Greg
 
Just a quick note on this. I shot some of the NEW PRODUCTION Starline 6.8 yesterday in 6.8 and 6X6.8 form. This stuff is the bomb!! No swipes/ejector issues. No bent rims and it looks pristine after shooting. 1000 % better than the first run. I've been in contact with Starline since the first stuff came out and they have been most accommodating in explaining the revisions. The first stuff was fine for SAAMI losdings but long term the heads would not hold up although the second firing on it in 6X6.8 was much less damaged and the pockets were still nice and tight.

Greta company and I'll be getting more of this.

Greg

PS: I'm getting some Grendel stuff to try also from them for the LBC's. If it's this god it will be the best alternative to Lapua on the market.
 
Greg, how can we get some of this new starline brass of this second production? I’d like more then the little I have now to form into 6x6.8. Is it available yet or is only the first stuff available? I’m definitely going to be loading in order to get as many as possible reloads out of my brass that I can and if this is as good as you say, which I have no doubt it is coming from you Greg, then I want some of this new production brass.
 
I chatted with them this AM. The new stuff is all that's on the shelf. Order it up guys.
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Greg
 
Greg, I loaded up 3 this afternoon. 30grs XBR 58gr Vmax. All chambered and cycled good, gas block wide open. All 3 cases landed 3:30 and all would have landed in a gallon paint can. The brass overall length did shrink .001" Shoulder set forward .005" after firing. Neck diameter was a good round .274" the thickness measured.012 to .013". I resized one of the fired cases with .002" bump on the shoulder. I measured the neck thickness and it was .012 to .014". Going to load up 30 and put on paper. Still don't have anything to measure lands. Do you have a clue about what COAL for a 58gr Vmax would be .020" of lands? Thanks, Jim. And thanks for the heads up on Starline
 
I'll look up my numbers in the AM. Id be getting that tool on order soonest so you can have confidence in your work. One suggestion is when you get it check the distances on the various bullets you want to try and keep those bullets for reference. Using a fired case you can size the body down and not move the shoulder for your gage for that barrel. With a new bullet and that case with the tool you'll have your number in about two minutes. Start a notebook and keep track of all the numbers.

Greg
 
I am going to order a tapp to make a test cartridge for my stoney point tool. I no you recommend the wilson, but I'm already in with the Stoney with about 11 calibers and have had great results. I keep a note book on ever gun & caliber. My buddies make fun of me and say I need to take a Secretary with me when I shoot but I figured out a long time ago that paper is better than memory and pretty cheap too.
 
I have used the Hornady and made a bunch of my own cases. I found that the Sinclair was much faster and repeatable for me. It so easy just to grab one of the first rounds fired and use it in the Sinclair with no work at all. I would say I have about 40+ cases in my little box of reference supplies.

I have never recommended a Wilson.

Greg

PS: I don't keep notes. I keep novels. Every rifle has a section in one of the spiral binders and 90% of the load targets I shoot are kept in the 3 ringers along with the Excel spreadsheets of load data that are printed copies of my computer files.

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I'm sorry it was Sinclair you said you favored. Nice Library looks more organized than mine. My buddies would say OCD "Overdoing Cartridge Development" but I can generally put it on em in a shoot off. I am probably going to have more questions when I get fine tuning the new caliber. Thanks for all your input.
Jim
 
I can say that with out these records I would be repeating myself constantly. I've got an issue with one barrel right now and I'll go back and pick some loads that shot well at two levels to reevaluate the tube. Not happy as what I'm seeing doesn't make a lot of sense right now but it's a mundane chambering. It may well be a matter of that tube just hating THAT bullet. Luckily I have three or four other alternative pills..lol

Questions? I have not had a week go by in two years when I'm not helping out someone. The good guys I help send me their results and don't just disappear of into the sunset.

Greg
 
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First # is weight second # is unfired new 3rd number is fired. these are for 6.8 SPC.


STARLINE 121.4 34.88 36.08
FC 119.8 35.18 36.18
REM 119.66 34.96 35.9
SSA (OLD) 111.36 35.88 37.8
HORN (FIRED) 129.0 35.58


The 6X6.8 is below.
ALL FIRED

6X6.8
FC 123.36 (20”) 35.24
SSA 115 (24”) 36.66
SSA (20”) 35.5
SSA 114.74 (24) 36.24


I'll get a fired 6X6.8 on the SL later and on the 6.,8 version.

No S&B in the house.

Greg
 
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